Telephone system with universal cord-circuit.



0. s. wmsmw, TELEPHONE SYSTEM WITH UNIVERSAL GORD CERCUIT.

APPLICATION FILED JULY 30 I914.

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APPLICATION FILED JULY 30,1914w GHARLESS.WINSTO1\T, or CHICAGO! ILLINOIS, ASSIGNOR 'ro KELLOGG SWITCI-IBOARD &

SUPPLY COMPANY, or CHICAGO, ILLINOIS, A CORPORATIO1\T or ILLINOIS.

. TELEPHONE SYSTEM WITH UNIVERSAL CORD-OIRCUIT.

L255,3Mt.

Specification of Letters Patent.

Patented Feb. 5, Iain,

Application filed July 30, 1914. Serial No. 854,906.

residing in Chicago, county of Cook, and

State of Illinois, have invented certain new and useful Improvements in Telephone Systems with Universal Cord-Circuit, of which the following is a specification.

'My invention relates to telephone systems and has to do more particularly with a telephone system with a universal cord circuit used for interconnecting lines of ditferent character such as manual and automatic.

' The preferred form of my invention is cspecially adapted to operate in connection with private-branch exchange systems such as are extensively used in hotels for interconnectin local telephones terminatingat the brane exchange switchboard. A feature of my invention is the improved circuit arrangement of auniversal cord circuit which is used for interconnecting local lines at-thebranch exchange or as the case may be its calling line at the branch exchange wish' sgto talk to an outside line terminating at an automaticexchange the party callin g informs the operator thata connection is desired with an automatic line. The oper ator then connects the calling local line with one of a number of trunk jacks terminating at the branch exchange switchboard, the connected trunk'jack extending the c0nnected local line to the automaticexchange. The telephones-at the branch exchange are preferably provided with impulse sending .de-

vices, the switch mechanism at the automatic exchange being operated throughthe cord circuit of the branch exchan e. Other features of my invention will e pointed out in the ensuing specification, and claims.

My invention is adapted for other uses but for the purpose of describing it l have shown acertain form and now refer to the.

accompanying drawings in which Figure 1, Part 1,.illustrates a cord and two link circuits of a private branch exchange, together with. atrunk circuit extending to an automatic exchange as shown of the line .to send impulses through the universal cord "Eircuit C to operate the switch mechanism of the automatic exchange. The substation A is connected by the line limbs 3 and 4 to the line circuit L which comprises a line relay LR, line signal LSand the jack J. The universal cord circuit C comprises answering and calling plugs P and P connected by the heavily marked conductors and having condensers K and K interposed. The answering end of the cord circuit is provided with an answering supervisory relay AS which con trols the supervisory signal SS and also acts as an impulse relay when a local line as A is connected by means of the cord circuit C to an automatic exchange. Relay AS being in bridge of theconductors T and S is responsive to the impulses of the calling device CD to operate the switch mechanism of the automatic'exchan e.

The shunting relays S ll and SU are as sociated with the answering end of the cord circuit and are operated upon the energization and deenergization of the relay AS when affected by the actuated calling device. Relays SU and SU being slow acting are not affected by the quick interruptions of the contacts of relay AS but remain energized during each set of interruptions of relay AS. The two relays SU and SH remain actuatedduring each set of impulses v and short circuit or shunt the polarized supervisory relay PSR. The polarized relay PSR is associatedwith the calling end of the cord circuit C and controls the supervisory signal SS A switching relay SW' is also associated with the calling end of the cord circuit C and is actuated only upon the cord circuit C being connected to another local line and this actuation places the polarized relay PSR inoperative relation with cord circuit C, so that when the called local line answers the polarized relay PSR operates'to efiace the signal SS A listening key LK is also provided which when thrown connects an operators set 0 in circuit with cord circuit C and a ringing key RKis also provided which when thrown connects the ringing generator G in circuit.

' To the right of the drawing 1 have illustrated a substation B similar to A, being connected by the line limbs 3 4 to a line circuit L comprising the line relay LE line signal LS and jack J Referring now to the automatic apparatus illustrated, which operates .in connection with the universal cord ,circuit C, I show a trunk jack TJ, the ack' being located at the branch exchange to which connection can'be made by the' cord circuit C. The jack terminates in an individual line switch D which comprises a line relay LR", cut-off relay CO and motor magnet MM, wipers 5, 6, 7 and the ofi-normal contact ON. The line relay LE is energized when connection is made with the jack TJ and its operation in turn energizes relay CO to connect motor magnet MM to step wipers 5, 6 and 7 to select an idle connector E. A busy back BB is provided which is connected incase the individual switch D does not find an idle trunk. The connector E which is of the Strowger type comprises an impulse relay IR, a private relay PV. a secondary relay SR, a vertical magnet VM. A rotary magnetRM is provided which is energized by the last set of impulses to step the wipers 11, 12, 13 in a rotary direction to select the contacts of a wanted line. A busy relay BR is ilSSOCl21""ll with the connector to connect busy back BB in case the called line is busy. A ringing relay BI is intermittently energized and deenergized by an interrupter I to connect the ringing generator G to ring the called line. A ringing control relay RCR is energized when the calling substation answers to disconnect ringing generator G. A release relay RR and a release magnet REM are associated with the connector,

. the magnet REM being energized upon the deenergization of the relay RR to release the switch mechanism. An off-normal contact ON 1s associated with the connector .and assumes its off-normal position upon the first step of the wipers' otf-normah The side switch wipers 17, 18, 19, 20 are stepped to their diiierent positions by the restoration of the relayPV.

An automatic substation B is shown to the right in Fig. 1, part 2, being similar to that of A and B and being connected by the line limbs 3 and 4 to its associated individual line switch D similar to D.

Having described in general the apparatus associated with my invention the operation will now be described.

Operation.

Assuming that av party at the local substation A wishes to converse with a party atthe local substation B, the party at substation A removes his receiver energizing the line relay LR from battery through normal contact 21 of the jack J, line limb 3 through the substation, line limb 4, normal contact 22 to ground, closing its alternate contact 23 to light line signal LS and the operator noting the signal LS inserts plug P into jack J The insertion pf the plug P into jack J opens the circuit of the line relay LR at the contacts 21 and 22 of ack J, the line relay restoring and eitacing the line signal'LS. The supervisory or impulse relay AS is also energized, circuit. being traced from battery through the lower winding of relay AS, sleeve contacts of plug P and jack J, line limb 3, through the substation, line limb 4, tip contacts of the jack J and plug P, the upper :winding of relay AS to ground, the relay AS encrgizlng and opening its contact 24 which prevents the supervisory signal SS from lighting. The relay AS energizing also closes its alternate contact 24 energizing shunt relay SU The operator then throws her listening key LR and finding that local substation B is wanted inserts plug P into jack'J energizing switching relay SIV over a circuit traced from battery to ground at the sleeve contact of the jack J The operation of relay SIV closes a circuit for supervisory lamp SS from battery through lamp SS alternate contact 25, relay SIV to ground at normal contact 26 of the polarized supervisory relay PSR.- The operator then throws ringing key BK to connect generator G to signal the called for line. The subscriber at the local substation B answering closes a circuit for the polarized supervisory relay PSR- traced from battery through alternate contact 27, of relay SlV, winding 28 of relay PSR, sleeve conductor S, sleeve contacts of the plug P and jack J line limb 41 through the substation, line limb 3 tip contacts of jack J and plug 1, conductor T, conductor 29, normal contact 30 of relay SU, conductor 31, the winding 32 of relay PSR to ground at alternate contact of the relay SW. The polarized relay operates and the contact 26 assuming its alternate position opens thecircuit of the supervisory signal SS eifacing it. The two substations A and B are now in conversational circuit, this circuit being traced over the heavily marked conductors. When the party at the local substation A replaces his eeeiver relay AS is deenergized closing a circuit for supervisory signal SS traced from battery through SS, normal eontact 24 to ground at the sleeve contact of jack J lighting the signal SS. The party at local substation. B replacing his receiver opens the circuit for polarized supervisory relay PSR which again closes circuit for supervisory lamp SS which again lights The deenergization of relay AS also opens circuit for relay SU. The operator noting the signals SS and SS removes plugs I and P Local to automatic.

Assuming now that the local substation A at the private branch exchange wishes to converse with an automatic subscriber as B whose line terminates intoan automatic exchange, the party at the local substation A removes his receiver which energizes line relay LR and lights the line 'signal LS. The operator noting this signal inserts plug P into jack J opening the circuit of line relay LR at the jack J which relay restores and effaces line signal LS. The insertion of the plug P into jack J also energizes the relay AS, which operates and opens the circuit for the supervisory signal SS preventing it from lighting. 'The relay SU energizes through alternate contact 24 of relay AS to ground at the sleeve of the jack J. The operator throws the listening key LK and upon finding that it is the automatic substation B which is wanted she inserts plug P into a jack TJ. The switching relay SW does not operate as the sleeve of the trunk jack T J is on open circuit. The insertion of the plug P into jack TJ operates line relay LR of the'individual line switch D, traced from battery through the winding of the relay LR the wiper 6, conductor T n'ormal contact 34 of relay CO, tip contacts of jack TJ and plug 1P normal contact of relay SU and alternate contact 43 of relay AS in multiple, winding 32 ofrelay PSR, normal contact 33 of relay SW, winding 28 of relay PSR, sleeve contacts 0t the plug P and jack TJ, normal contact 35 of relay CO, wiper 7 to ground. The energization of relay LR closes an energizing circuit for cutofi. relay CO from ground at alternate contact 36 of relay LR normal contact 37 of off-normal contact ON, normal contact 38 of the cutofi' relay CO, through the winding of CO to battery. The energization of relay CO closes an energizing circuit for motor magnet MM traced from 'ground at alternate contact 39 of relay LR alternate contact 40 of relay CO through winding of motor magnet MM to the generator G Motor magnet MM steps wipers 5, 6 and 7 of the individual switch D over the contacts 8, 9 and 10 to select an idle connector. The oii-normal contact ON assumes its alternate position on the first step of the wiper 5, 6 and 7, but relays LR and CO remain energized as long as the wipers 5, 6 and 7 are passing over grounded contacts, but as soon as the wiper 5 finds an ungrounded contact the circuit of the relay CO is opened to deenergize the magnet MM to prevent the wipers from be ing stepped beyond the selected contacts, the relay lLR remaining energized from ground at the private contact of the connector. Assuming that the number of the called automatic substation is 45 the party at the local substation A actuates his calling device CD to send the diiferent'series of impulses to select the called-for automatic station B The relay AS of the cord circuit C is bridged across the line conductors T and S when the plug P is in the jack J, and when the calling device CD of the calling'local substation A is actuated to send a certain number of im pulses'the relay AS being bridged across the line conductors of the cord G is energized and deenergized to open and close its contact 43 to eiiect the automaticapparatus to select the called line. When the calling device CD is actuated to send four impulses of current, which we will assume is the first digit of the called automatic substations number, the opening and closing of the contacts 1 and 2 of the calling device CD interrupts the circuit of the relay AS 4 times. Upon deenergization of AS relay SU is energized from battery through its winding, normal contact 24 of relay S, sleeve contacts of the plug Pand jack J to ground.

The relays SU and SU being slow acting relays are not affected by the rapid interruptions of the contact 24 and therefore remain energized while the impulses are being sent. The energization of the i elays SU and Sl will close a short circuit around the winding of the polarized relay PSR which may be traced from the point 44, conductor 45, alternate contact 46 of relay SU. alternate contact 47 of relay SU to point 48 thus shunting out the relay ISR while the impulses are being sent. The encrgization and de'nergization of relay AS opens and closes the circuit at the contact 43.

When the connector was selected. its relay IR was energized, the circuit being traced from battery through the upper winding of relay IR, normal contact 41 01 reversing relay RV, conductor T contact 9ywiper 6, conductor T tip contacts of the plug P and jack TJ, conductor 29. contact 43, windings of PSR, sleeve of jack and plug, wiper 7 and contact 10, normal contact 42 of relay RV, the lower winding of the relay IR to ground. The operation of the relay IR closes an energizing circuit for the release relay RR traced from ground through alternate contact 50 of relay IR and the winding of relay RR to battery.

The subscriber at the local substation A havingactuated callingdevice CD to send four impulses which energize and deenergize the relay AS to interrupt its contact 43, said interruptions operating the relay IR four times. On the first deenergization of relay IR an energizing circuit for secondary relay SR and vertical magnet VM is established, traced from ground through the normal contact 50 of relay IR, alternate contact 51 of relay RR, the winding of rewipers 11, 12 and 13 to the fourth level of the switch contacts. The relay SR remains energized while the impulses are being sent and theclosure of its alternate contact 90 establishes an energizing circuit for the private relay PV traced from battery, thewinding of the relay- PV and the alternate contact 90 of relay SR to ground. After the first set of impulses relay PV deenergizes having its circuit opened at the alternate'contact 90 and mechanically steps the side switch wipers 17, 18, 19 and 20 to their conductor 58, winding of magnet RM, side switch contact 54, side switch wiper 18 tobattery. The rotary magnet being also a quick-acting relay is responsive to the quick interruptions and steps wipers'll, 12 and 13 to the fifth contacts of the fourth level which are the contacts of the wanted line,

' the oil-normal contact 0N assuming its alternate position upon the first step of the switch movement. After this set of. impulses are sent, the relay PV again restores having its circuit interrupted at contacttlO,

and the relay AS of cord C remains in its operated condition opening the circuit of the relay SU which removes the shunt from the polarized relay PSR, which again operates from battery through upper winding of IR, normal contact 41, conductor T ,normal contact 34-of relay CO, tip contacts of the jack TJ and plug P conductor T, conductor 29, normal contact 30, conductor 31 to the point 48,through the winding 32 of the relay PSR, normal contact 33 of relay SW winding 28 of relay PSR, conductor S, sleeve cont-acts of the plug P and jack TJ, normal contact 35 of relay CO, conductor S normal contact 42, lower winding of relay IE to ground. This energizes polarized supervisory relay PSR and the closing of its alternate contact 26 again lights the supervisory lamp SS from battery through the lamp, normal contact 25, of relay SlV, alternate contact 26, of relay PSR, to ground, the lamp SS remaining lighted until the called subscriber answers.

After the lastset of impulses the private relay PV- deenergizes stepping the side switch wipers 17, 18, 19 and 20 to their third position engaging the contacts 59, 60, 61 and Upon each deenergization of relay' 62; The wiper 18 engaging thecontact closes an energizing circuit for the ringing relay RI traced from battery through the side switch-wiper 18, conductor 63, normal contact 64 of relay RCR. the windin of relay RI, through the interrupter f to ground. The relay R1 is energized and deenergized by the interrupter I to connect the ringing generator-G through the alternate contacts 65 and 66 of the relay R1 to intermittently ring the call bell of the calledfor substation B lVhen the party at substation 13 removes his receiver from the switch hook, in response to the call the reversing relay RV operates, the circuit being traced from battery through its lower winding, normal contact67 of relay PV, conductor S normal contact 66 of relay RI,

wiper 13, contact 16, line limb 4 through the substation, line limb 3 contact 15, wiper 12, normal contact 65, conductor T normal contact 68 of relay PV, the upper winding of relay RV to ground. The operation of the relay RV reverses the original battery flow through the relay PSR of the cord circuit O causing the restoration of the relay PSR and eifacement of signal SS. The operation of the reversing relay RV also closes ail-energizing circuit for the ringing control relay RCR traced from battery through the windingof the relay RCR, conductor 69, alternate contact 70 of relay RV, conductor 71, side switch wiper 17 to ground at contact-59, the energization of the relay RCR opens the circuit for relay RI at its contact 64, the ringing relay RI deenergizing and thus cutting off the ringing current when the called subscriber answers. The relay RCR closes a locking circuit for itself traced from battery through its winding, its alternate contact 72, conductor 71 to ground at contact 59, th e relay remaining locked up to prevent ringing current being connected to the called line while conversation is going on, the relay remaining locked up until the parties disconnect.

After conversation has been completed, the party at the substation B replaces his receiver upon its switch-hook, this not opening the energizing circuit of relay RV, which again restores ancl causes a reversal of battery which again operates the relay PSR to close its alternate contact 26 to ground lighting supervisory lamp SS and thus notifying the operator that the called subscriber has replaced his receiver. The party at the substation A replacing his receiver upon the switch-hook deenergizes relay AS lighting lamp SS and the operator withdraws plugs 'P and P thus opening the circuit of inter- Jill to the removal at ground the test conductor 99 at alternate contact 75 of relay RR. This removal of ground permits restoration of LB of line switch D whereupon its normal contact 3'6 is closed causing the energization of CO. Relay CO being energized and relay LE being deenergized, both retaining pawl-s are withdrawn and the wipers restored to normal as will be clear .trom an inspection of Fig. 2.

Assuming that the subscriber at the local substation A has operated the calling device CD to send the last set of impulses which are live in number to select the wanted line of the called substation and if the called substation is busy a ground will beconnected to the private contact 14 of the called line from the alternate contact 36 of theindividual switch D. This ground will establish an energizing circuit for the'busy relay BR traced from battery through its upper winding, the side switch contact 53, switch wiper ing been sent and a busy line encountered by the connector wipers and due to the relay SR beinga slow acting relay it remains energized momentarily preventing the private relay lPV from releasing until another circuit is established for it in series with the lower winding of the relay BR. The relay PV int remaining energized when the connector engaged a busy line does not step the side switch wipers. they remaining in their second position. The operation of the relay BR connects busy back BB through alternate contact 7 9 of relay BR. side switch contact 56, side switch wiper 20which now is in its second position, conductor S back to the calling substation, this busy signal notitying the calling subscriber that the called line is busy. The subscriber at A in replacing his receiver opens the circuit of the relay AS. which restores again lighting the signal SS. The relay RV of connector IE.

not operating does not reverse the battery flow for the relay PSR of the cord circuit C and therefore the signal SS remainslighted. The operator noting the two signals SS and SS removes the plugs from their respective jacks which efiaces the signals. The restoration of the automatic apparatus being the same as before described.

Although in illustrating my invention I have shown an individual switch D and connector E for use in extending the calls from the private branch lines to the automatic exchange lines, it-is to be understood that this is only for the purpose of illustration and l contemplate using my invention with larger sized exchanges which include first and second selector switches. and therefore Flt do not desire to be limited to the exact arrangement as disclosed. but aim to cover all that which comes within the spirit and scope of the appended claims.

Having described my invention what it claim as new and desire to secure by Letters -Patent is:

l. A telephone system comprising private branch exchange telephone lines. a cord circuit for interconnecting said lines, trunk circuits extending from the switchboard at the private branch exchange to an automatic exchange. a polarized relay connected in bridge of the calling end of the cordcircuit,

a source of current and means for connecting said source in circuit with said polarized relay when connection is made between the calling end of the cord and a private branch line to furnish transmitter current to said line, circuit connections whereby said polar ized relay is connected in bridge of the automatic trunk exclusive of said sourceof current when the calling plug is connected with said automatic trunk, and a relay for said cord circuit under substation control for transmitting impulses over said automatic trunk.

2. A telephone. system comprising telephone lines,-a-cord circuit for interconnectlng said lines, a trunk circuit extending from .the switchboard of said lines toan automaticexchange, a two coil polarized relay at the call ng end of the cord circuit. a source of current and means. for connecting said source in circuit with said polarized relay coils at an intermediate point and in bridge of said cord circuit when connection is made between the calling end ot-the cord and one of said lines to furnish transmitter current to said line, circuit connections whereby said source of current is excluded and saidpolarized relay coils are connected in bridge of the automatic trunk when the calling plug is connected therewith, and a relay for said cord circuit for repeating impulses from a calling one of said lines over said automatic trunk to said automatic exchange.

' 3. In a telephone'system, a calling subscribers line, a link circuit connected thereto provided with a polarized relay associated with the calling end thereof, called subscribers lines of differenhcharacters, means forconnecting the calling end of said link circuit to the said called lines, means for either directly bridging the said polarized relay across said link circuit or for including a source of transmitter current in said bridge, said last means being dependentupon the character of the called line connected with, and a relay associated with the answering end of the cord circuit for shunting said polarized relay.

4. In a telephone system, a calling subscribers line, a link circuit connected thereto,

a called subscribers use, automatic switch temporarily associated with said link circuit and having access to said called subscrlbers line, a supervisory relay'bridged across the calling end ofthe' said link circuit, and means controlled -by ;the calling subscriber when operating said' automatic switch for shunting said supervisory relay.

5. In atelephone system a calling subscribers line, a plug ended link circuitconnected thereto provided with a combination supervisory and impulse control relay, called subscribers lines of different characters, means under the control of a central ofiice operator for connecting said link circuit to a called subscribers line of one of said characters, and means including said combination relay for extending a connection from said link circuit to acalled subscribers line of another of said characters.

6. In a telephone system, a calling subscribers line, a link circuit connected there-' lay to the link circuit, and a relay for elec- 'trically connecting together the talking strands of the cord circuit at the calling end thereof.

7. A telephone system including a calling subscribers telephone line, a link circuit for connection thereto, an automatic trunk circult for connection with the other terminal of said link circuit, a supervisory relay connected across the calling end of said link circuit, and a relaycontrolled by the calling subscriber for shunting said supervisory relay.

8. A telephone system including a calling subscribers line and a called subscribers line, a link circuit for connecting said lines in a conversational circuit, a supervisory relay bridged across the calling end of said link circuit, a combination supervisory-and impulse relay bridged across the answering end of said link circuit, and means controlled over the calling line for operating said combmation relay to shunt sald supervisory relay.

9. A- telephone system including a calling subscribers line, an automatic switch, an operators l1nk circuit for connecting said su scribers line to said automatic switch, a combination supervisory and impulse relay bridged across the answering end of said link circuit, and subscriber controlled means for operating said relay to transmit impulses to said automatic switch.

10. A telephone system including a calling subscribers telephone line, an automatic selector switch, an operators connecting circuit for connecting said calling subscribers line to said automatic switch, a combination supervisory and impulse relay for said con-- necting link, a supervisory relay bridged across the calling. end of said connecting link, means controlled by said'first relay for shunting said second relay and for transmitting impulses to said automatic switch, and

subscriber controlled means for operating said first relay.

Signed by me at Chicago, county of Cook and State of Illinois, in the presence of two witnesses.

CHARLES S. WINSTON. Witnesses:

GEORGE E. MUELLER, WM. BERGHOLM. 

